Folding means for paper sheet products, known as signatures, that are moved thereinto on a conveyance belt to be cross folded or quarter folded are known in the art as quarter folders. Typical of this art is the system disclosed in U.S. Pat. No. 3,995,850, Dec. 7, 1976 to K. Hertrich et al. wherein paper products are conveyed by a conveyer belt into a folding station. However, when such folders are required for high speed processing equipment such as high speed web printing presses and the like, there has been a problem because of the need to stop the paper product at the folding station prior to the actual folding operation to guarantee an accurate and consistent fold. If a paper product is moved into a stop at the folding station at high speed the inertia and momentum will cause the product to bounce or collapse spasmodically, resulting in irregular folds. Thus, the quarter folder has been a speed bottleneck limiting rotary press speeds to 25,000 to 30,000 per hour when an accurate quarter folded product is required. Some typical solutions in the prior art are represented by U.S. Pat. Nos. 4,279,410 issued July 21, 1981 to H. B. Bolza-Schunemann for putting a plurality of the folders in parallel to respectively receive the paper products diverted off the conveyance line, and 2,821,386 issued Jan. 28, 1958 to J. R. Petre for non-linearly moving a folder blade into the product in order to overcome impact problems of the folder in an effort to improve the throughput speed.
Nevertheless, in all the known prior art, there has not been any suitable means to speed up significantly the rate of quarter folding products delivered on a high speed conveyance belt more than a few thousand products per hour attained when the products delivered on a high speed conveyance belt are slowed down a small percentage (approximately 8%) of the delivery rate before the impact of the product upon the fixed stop at the folding station.